Images can be represented as electronic versions of the scene being viewed. The electronic image may represent a scene to that has a very high dynamic range, e.g. 18 bits or more of dynamic range. However, conventional display devices typically only display 8-bit-images. Therefore, it is often necessary to display a higher dynamic range scene on a lower dynamic range viewing device.
If the same quantization step is used in an attempt to make this display operation, then either the brightest part of the image or the darkest part of the image is often lost.